Road intersections represent critical points of a road system due to the interferences that occur between various traffic streams. Thus, there arises various problems on the roads regarding traffic safety and circulation regularity.
At a road intersection, a vehicle performs various manoeuvres, among which changing speed and/or direction, which cannot be performed freely, due to the presence of other vehicles. In particular, when joining the traffic stream (active entry) the driver of the vehicle joining the traffic stream must make sure he has enough space between the vehicles transiting in the traffic stream. The drivers of the vehicles transiting in the main traffic stream of a road or lane must be in turn able to control the manoeuvre of the other vehicles joining the traffic stream (passive entry).
For the safe operation of the road intersections the vehicles nearing a road intersection or about to perform a manoeuvre to join the traffic stream should be able to mutually see each other hence adjust their driving conduct according to the regulation modes of the road intersection itself.
Use of special acceleration or entry lanes on at-grade or raised intersections, provided with interchanges, eases traffic flow drawbacks deriving from manoeuvres to join the traffic stream. In this case, the junction region between the specialised manoeuvre lane (entry lane) and the main lane or road to which the entry lane is joined tangentially—the region where the manoeuvre to join the traffic stream is performed—comprises a parallel section and a junction section.
The entry of the vehicle into the main traffic stream, towards a destination direction, occurs along a variable direction of manoeuvre and ends along a direction of joining the traffic stream incident with the destination direction according to an acute angle.
This causes difficulties for the driver, who must check the traffic approaching from behind with respect to the direction he is travelling to join the traffic stream with the assistance of the vehicle rear-view means, typically internal and external rear-view mirrors or one or more video cameras, given that he cannot have a direct view turning his head, as he would do in common perpendicular intersections.
However, in this case, the rear-view means are not always oriented in such a manner to show an image including the lane or destination road, making the driving condition still hazardous.
The current systems for picking up scenes of the environment surrounding the vehicle (for example the driving assistance systems for blind spot monitoring, BSM) do little to overcome such drawbacks in that they are complex systems arranged to acoustically warn the driver or which require the driver to look away, when naturally looking at the rear-view mirror, to project the image of interest elsewhere, typically on the windscreen, on the dashboard or on the instrument panel.